Send ill sex avian flu high to be in all can happen all the year round, section of Dan Yidong spring is sent more. Main reason is:

The first, flu virus is more sensitive to temperature, as environmental temperature elevatory, virus surviving time shortens. Additional, strength of illumination of summerly autumn season is relative taller, the ultraviolet ray in sunshine has to virus very strong exterminate action.

The 2nd, birdhouse of Xia Qiu season is ventilated intensity is far outclass winter spring, good ventilated and OK the amount of the virus in reducing henhouse environment greatly, accordingly, virus invades the opportunity inside gallinaceous body and amount to decrease apparently, infection odds drops. At the same time good ventilated also reduced the undesirable gas stimulation to mucous membrane of gallinaceous respiratory tract, have important sense to maintaining the strength of respiratory tract mucous membrane.